Flashing ECU with different car key

[MartinF1]

Hello
Does it matter if I read the file from ECU via OBD port in the car with one car key and then want to flash it back with spare key from the car?
Should I have any problems?

[jurebv]

if both key work and are able to start the car, no problems

[MartinF1]

Thank you, I hope I won't have any problems :P